Mechanical pipe couplings provide various advantages over other techniques for joining pipe elements end to end. For example, they are less expensive to install than welded joints, which require skilled welders and the use of an exposed flame or arc, which are not practical or safe in every environment. Mechanical couplings may also be designed to afford a degree of flexibility at the joint, unlike welded joints which are substantially rigid. Flexibility is desired because it facilitates design and assembly of the piping network, allowing for larger dimensional and angular tolerances. It also allows for greater expansion and contraction under temperature changes without compromising the fluid tight integrity of the various joints. It would be advantageous to have a mechanical pipe coupling which is usable with standard groove pipe and which provides for angular flexibility of the pipe elements without compromising the fluid tight integrity of the joint.